1. Field of the Invention
The present invention relates to a method of manufacturing a liquid droplet ejection head, and more particularly, to a method of manufacturing a liquid droplet ejection head provided with a water repellent film on a surface of a nozzle plate of the liquid droplet ejection head.
2. Description of the Related Art
In the liquid droplet ejection head that is used in the liquid droplet ejection device, for example, in an ink-jet recording device, when ink is adhered to a surface of the nozzle plate, an ink droplet ejected from a nozzle is affected, and thus a variance may occur in an ejection direction of the ink droplet. When the ink is adhered, it is difficult to cause the ink droplet to land at a predetermined position on a recording medium, and thus this becomes a cause of deteriorating an image quality.
Therefore, a water repellent film is formed on the surface of the nozzle plate so as to prevent ink from being adhered to the surface of the nozzle plate and to improve an ejection performance. When the water repellent film is formed on the surface of the nozzle plate, a meniscus is formed in a nozzle section. The meniscus, which is formed at the nozzle section in this manner, prevents a liquid (ejection liquid) ejected from the nozzle from overflowing from the nozzle. When the water repellent film is not provided on the surface of the nozzle plate, the ejection liquid overflows to the surface, and thus it is difficult to control an accurate ejection volume or an ejection direction. In addition, when the water repellent film is formed on the surface of the nozzle plate, it is possible to cause waste such as paper dust, foreign matter, and dried matter from liquids to be not likely to adhere to the surface of the nozzle plate and solidify. When liquid is adhered to the surface of the nozzle plate, this leads to adhesion of the waste, foreign matter, solidified matter, or the like. In addition, the surface of the nozzle plate is generally wiped during periodic maintenance. However, when foreign matter, solidified matter, or the like is adhered to the inside of the nozzle during wiping, ejection is significantly hindered.
On the other hand, in the case of forming the water repellent film on the surface of the nozzle plate, when the water repellent film is formed in a state in which the nozzle is opened, the water repellent film is also adhered to the inside of the nozzle. When the water repellent film is formed inside the nozzle, a meniscus is formed at a position further inside the nozzle. As a result, the ejection volume or the ejection direction becomes unstable, and thus a non-ejection may occur. In addition, when the inside of the nozzle is to be filled with liquid, wettability is poor, and thus air bubbles are easily become entrained. When the air bubbles are entrained, non-ejection may occur in the nozzle. In addition, the air bubbles propagate inside the filled liquid and transit to other nozzles, whereby other nozzles are affected. Therefore, as a method of removing the water repellent film adhered to the inside of the nozzle, various methods have been reviewed.
For example, as a method of removing the water repellent film that flows to the inside of the nozzle and is adhered thereto, JP2007-261070A discloses a method in which the surface of the nozzle is protected by an elastic body or a masking material and an inner water repellent film is removed by plasma from an inner side of the nozzle. JP2008-221653A discloses a method in which a liquid repellent film is formed on the surface of the nozzle plate, a protective member is provided to a nozzle opening and the periphery thereof in a non-adhesive manner, and the liquid repellent film is removed. In addition, JP4374811B discloses a method in which a photosensitive resin is used as the protective member, and the inner water repellent film is removed by plasma from the inner side of the nozzle.